"If the design of everyday objects were ruled by aesthetics, life might be more pleasing to the eye, but less convenient; if governed by the utility, might be more comfortable but uglier. If costs or ease of manufacture predominate, it is possible that the products were not even attractive or functional or durable. "(NORMAN, 1988)

Obviously any everyday object is a compendium of three concepts -aesthetics, utility and costs, equilibrium between them is essential. The problem comes when one of the three predominates over the other, the designer must know how to give each part the value it deserves.